Compound engine



(N0 Model.) 1

I. H. VAILE. COMPOUND ENGINE.

No. 406,317. Patented July 2, 1889.

fi ATTORNEYS.

WITNESSES:

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UNITED STATES PATENT OFFlCE.

JOHN H. VAILE, OF DAYTON, OHIO.

COMPOUND ENGINE.

SPECIFICATION forming part of Letters Patent No.406,317, dated July 2, 1889.

Application filed May 10, 1888. Serial No. 273,495. (No model.)

To all whom it may concern:

Be it known that I, JOHN I1. VAlLE, a citizen of the United States, residing at Dayton, in the county of Montgomery and State of Ohio, have invented certain new and useful Improvements in Compound Engines, of which the following is a full, clear, and exact description, reference being had to theaccompanying drawings, forming part of this specification.

My invention relates to all classes of compound steanrengines; and it has for its object the increased efficiency and economy of this class of engines.

The novelty of my invention Will be herein set forth, and distinctly pointed out in the claims.

In the accompanying drawings, Figure 1 is a side elevation, partly in section, of the steam end of an engine embodying my invention. Fig. 2 is an enlarged sectional elevation of the automatic Valve mechanism.

The same letters of reference are used to indicate identical parts in both figures.

The construction of the concentric cylinders with a common piston-rod and the slidevalve mechanism is Well known in this class of engines, and need not be here described further than to say that A is the smaller cylinder, with its steam-chest B and slide-valve O, and D the larger cylinder, with its steamchest E and slide-valve F. The piston G of cylinder A and piston H of cylinder D are secured to one piston-rod I in the usual or any suitable manner. The slide-valves O F are secured to one valve-rod J, actuated in the usual or any suitable manner, and by their throw admit steam alternately to the opposite sides of the pistons through the usual or any suitable ports-in this instance double ports for the cylinder D, so as to obtain a better cushioning of the piston II. A pipe K connects the exhaust to of the cylinder A with the steam-chest E of the cylinder D, in the usual or any suitable manner. L is the livesteam pipe entering the steam-chest B, and havingabranch M entering the steam-chest E.

Heretofore in this class of engines it has been customary to provide an ordinary handvalve in the branch pipe or auxiliary pipe, which admits live steam to the steam-chest of thelarger cylinder, upon opening which valve, in starting the engine, live steam is admitted to the piston of the larger cylinder to overcome static pressure, inertia, and friction until the requisite speed and duty are obtained, at which time the valve should be closed by the engineer to cutoff the supply of live steam to the larger cylinder, and the exhaust-steam from the smaller cylinder be depended on for maintaining the pressure in the larger one. The engineers are frequently negligent, however, and permit the valve to remain open much longer than necessary, and sometimes even forget to close it at all, thereby to a greater or less extent defeating the compounding feature of the engine, causing considerable waste of steam and fuel.

It is the purpose of my invention to prevent such loss, as well as to maintain at all times the proper relative degrees of pressure in the two cylinders, by providing means for automatically controlling the admission of live steam to the larger cylinderin such manner that upon starting the engine the live steam is admitted to said cylinder until the requisite speed and duty are obtained, and is then automatically cut off and the exhauststeam from the smaller cylinder utilized to maintain the required pressure in the larger cylinder; but so arranged that if the latter is insufficient at any time to keep up the proper pressure in the larger cylinder live steam is automatically admitted to said cylinder until the proper pressure is restored, and is then again automatically out off. These results are accomplished by my invention in the manner and by the means to be now described.

Interposed in the branch pipe M,whieh admits live steam to the steam-chest of the larger cylinder at any convenient and suitable point, is the valve mechanism shown in detail in Fig. 2, where N is a valve-chamber, in which is a double disk-valve, the disks 5 c of Which are secured adjustably, if desired, upon the rod 0, Whose upper end projects through the stuffin g-box d, and is pivoted to an arm 6, which extends through a slotted stopguide f, and is provided. with an adjustable weight g, and whose opposite end is connected by a pivoted link h to lugs 1' upon the valvechamber. To aid the weight g in holding down the valx e-rod and disks Z) c, a coiled spring j, surrounding the rod 0 between the stufiing-box (Z and disk 0, may be employed, and the tension of this spring regulated by screwing the stuffing-box up or down, as desired. The live steam in starting the engine enters the valve-chamber through the port 7t" between the disks 1) c, which are of equal diameter, and therefore balanced, and passes on through the port land pipe M to the steamchcstE of the larger cylinder. An additional port m below the port Z opens into the valvechamber N beneath the disk 1).

Assuming, now, that the requisite degree of steam-pressure is sixty pounds on the piston G and twenty pounds on the piston II, the adjustment and operation of the parts are as follows: The valve in the pipe M is so adjusted by means of the weight g or spring j, or both of them, that it will require a steampressure of just twenty pounds beneath the disk I) to lift the valve and cause said disk to close the port Z. In starting the engine, the valve being in the position shown in Fig. 2, upon opening the main throttle-valve, admitting steam from the boiler to the pipe L and steam-chest of the smaller cylinder, live steam will enter the valve-chamber N through the port 7c between the disks 1) c, and pass out the port I through the pipe M to the steam-chest of the larger cylinder, and the engine will be immediately started with livesteam pressure on both pistons. As soon, however, as the pressure in the larger cylinder reaches the degree of twenty pounds the back-pressure through the pipe M and port m into the lower port of the valve-chamber N beneath the disk I) will exert itself on said disk and raise the valve to cause said disk to close the port Z and entirely cut oil the live steam from the larger cylinder. The exhauststeam from thesmallercylinder-passes through the pipe K into the steam-chest of the larger cylinder as soon as the engine is started, and is utilized to maintain the requisite pressure in said cylinder in the usual manner. If at any time the pressure in the larger cylinder, and consequently the pressure beneath the disk I) in the valve-chamber N, falls below twenty pounds, the weight g and springj will push said disk down to uncover the port I and admit live steam to the larger cylinder. As soon as the pressure in the latter is restored to twenty pounds the disk I) will be again lifted and the port Z closed.

\Vhile I have shown the automatically-operating valve as located in a branch pipe extending from the main steam-pipe to the steam-chest of the larger cylinder, it may, if desired, be interposed in an auxiliary pipe conveying steam directly from the boiler to said steam-chest; and while I have shown my invention as applied to a compound engine with concentric cylinders it is equally applicable to compound or triple-compound engines of other construction, whether their cylinders be concentric or notas, for instance, when they are side by side and their piston-rods are connected to cranks which are a continuation of each other on the same shaft and set at an angle to each other to prevent deadcenters.

Having thus fully described my invention, I claim 1. In a compound steam-engine, the combination, with the high and low pressure cylinders, of a passage for the exhaust of the high-pressure cylinder leading to the steamchest of the low-pressure cylinder, and a passage from the boiler for the simultaneous admission of exhaust and ,live steam to the steam-chest of the low-pressure cylinder, and a regulating-valve governing the admission of the live steam controlled by the pressure in the said steam-chest, substantially as described.

2. In a compound steam-engine, the combination, with the high and low pressure cylinders, of a pipe-connection between the exhaust of the high-pressure cylinder and the steam-chest of the low-pressure cylinder, and a live-steam pipe from the boiler to said steamchest for the simultaneous admission of steam to said steam-chest, and a valve in the steam? pipe from the boiler opened by an adjustable weight. and closed by the increase of pressure in the 10\V.-I)ICSSU1'Q steam-chest, substantially as described.

JOHN II. VATLE. 'itnesses:

WILLIAM H. RUssELL, ALLERT S. MARTEL. 

